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Front 1

SPHENOPALATINE ARTERY

Back 1

1. Sphenopalatine artery: arises from the maxillary artery within the
pterygopalatine fossa and enters the nasal cavity through the Spheno-
palatine foramen; divides into posterior lateral nasal arteries and poste-
rior septal arteries which supply the posterior parts of tlie lateral nasal
wall and nasal septum, respectively

Front 2

POSTERIOR ETHMOIDAL ARTERY

Back 2

2. Posterior ethmoidal artery: arises from the ophthalmic artery and
emerges through the posterosuperior part of the lateral nasal wall;
supplements the blood supply to the posterosuperior parts ot the lateral
nasal wall and nasal septum

Front 3

ANTERIOR ETHMOIDAL ARTERY

Back 3

3. Anterior ethmoidal artery: arises from the ophthalmic artery and enters
the nasal cavity through the cribriform plate; supplies tlie anterosuperior
parts ofthe lateral nasal wall and nasal septum

Front 4

SUPERIOR LABIAL AND GREATER PALATINE ARTERIES

Back 4

4. Superior labial and greater palatine arteries: arise troin tlie facial and
descending palatine arteries, respectively; enter the nasal cavity through
the nostril and incisive canal, respectively, and supply tlie anteroinferior
part ofthe nasal septum

Front 5

LATERAL NASAL ARTERY

VEINS

Back 5

5. Lateral nasal artery: arises from the facial artery; some ot its branches
supply the anteroinferior part ofthe lateral nasal wall

6. Veins: course with their corresponding arteries

Front 6

PARANASAL SINUSES

Back 6

III. Paranasal Sinuses
A. Mucosal-lined diverticula ofthe nasal cavity within tlie frontal, ethmoid,
sphenoid, and maxillary bones

Front 7

PARANASAL SINUSES

FRONTAL SINUS

Back 7

B. Frontal sinus: located superomedial to the orbital aperture within the squa-
mous and orbital parts ofthe frontal bone; its frontonasal iluct empties in-
feriorly into the ethmoidal infundibulum, which, in turn. drains into the nasal
cavity through the semilunar hiatus

Front 8

PARANASAL SINUSES

ETHMOIDAL SINUSES

Back 8

III. Paranasal Sinuses

C. Ethmoidal sinuses

1. Composed of about 10 thin-walled air cells located between the supe-
rior and middle nasal conchae and the orbital lamina of the ethmoid bone;
they are divided into three groups designated anterior, middle, and
posterior

Front 9

PARANASAL SINUSES

ETHMOIDAL SINUSES
-anterior ethmoidal air cells

Back 9

2. Anterior ethmoidal air cells drain into the ethmoidal infundibulum,
middle ethmoidal air cells lie within and drain onto the surface of the
ethmoidal bulla, and posterior ethmoidal air cells drain into the supe-
rior meatus